As the value and use of information continues to increase, individuals and businesses seek additional ways to process and store information. One option available to users is information handling systems. An information handling system generally processes, compiles, stores, and/or communicates information or data for business, personal, or other purposes thereby allowing users to take advantage of the value of the information. Because technology and information handling needs and requirements vary between different users or applications, information handling systems may also vary regarding what information is handled, how the information is handled, how much information is processed, stored, or communicated, and how quickly and efficiently the information may be processed, stored, or communicated. The variations in information handling systems allow for information handling systems to be general or configured for a specific user or specific use such as financial transaction processing, airline reservations, enterprise data storage, or global communications. In addition, information handling systems may include a variety of hardware and software components that may be configured to process, store, and communicate information and may include one or more computer systems, data storage systems, and networking systems.
Servers are one type of information handling system. The number of features included in current servers have grown to the point such that there is little, if any, volumetric room for new features. All system links and input/output (TO) interconnects may be completely consumed (Intel QuickPath Interconnect “QPI”, Advanced Micro Devices HyperTransport “HT” links, Peripheral Component Interconnect Express “PCIe” lanes, double data rate “DDR” channels). As an example, a current mainstream 2U Server may include two to four CPUs, 18 to 48 dual in-line memory modules “DIMMs”, 16 to 24 drives, 7 PCIe slots, and two power supply units (PSUs). The ratio of DIMM sockets typically included in mainstream servers has grown from two to three DIMM sockets per CPU socket in 2005 to 12 to 24 DIMM sockets per CPU socket in 2012. A considerable portion of the server internal feature volume is reserved for these DIMM sockets, but it is not uncommon for a server owner or operator to not fill all of the provisioned DIMM sockets with DIMMs.
It is typically desirable to provide a tiered main memory for an information handling system in order to optimize performance, cost, power, and Reliability/Availability/Serviceability (RAS). Many applications have large working sets needing efficient random reads, with reduced needs for efficient write operations. Examples of such applications include large databases and high performance computer cluster (HPCC) applications such as fast Fourier transforms (FFTs). Dynamic random access memory (DRAM) is expensive, rotation-media disk-drives have excessive latency, and conventionally accessed solid state drives “SSDs” (such as SAS-based or PCIe-based SSDs) have high processing overhead.
RAM disks or Ram drives have been implemented as a block or file storage in main volatile memory of an information handling system, and accessed via an operating system (OS) driver.